A composition of this invention is termed a metastable interstitial composite (MIC). MICs are a new class of energetic materials which provide much more flexibility in their use than unimolecular energetic materials. MICs will be useful in explosives applications and in applications where a source of gas or heat is needed.
When a conventional explosive, or energetic material, is detonated, the atoms of each molecule of explosive rapidly rearrange to form gaseous products while releasing energy in the form of heat and shock. One condition for such a chemical reaction to take place is that the atoms of the reactants must be sufficiently close together so that they will interact with one another. In such a unimolecular reaction, the atoms of the molecule are sufficiently close to one another for the reaction to take place by virtue of being bound in a single molecule. There exist pairs of materials which react to release large amounts of energy, but the release is not sufficiently rapid for the materials to be useful as an explosive composition. On the other hand, there are applications for energetic materials where conventional explosives cannot be used because the reaction proceeds too quickly.
MICs can be designed for both fast and slow reactions. The present invention includes chemical reactions between substances which have not previously been useful in applications requiring energetic materials. The reactions take place between atoms which are not bound together in a single molecule, but which are disposed sufficiently close to one another so that rapid chemical reactions will take place. This is accomplished by use of a composite having thin layers of reactants which are separated by thin layers of a material referred to as a buffer which prevents the reaction from taking place until an external triggering stress is applied to initiate the reaction. In addition to MICs which can be designed such that the reactions proceed rapidly, MICs which react more slowly can be designed. In general, MICs can be designed to suit the application. For example, if the application requires heat but not gasses, the MIC can be so designed.